Valve rotator



o. E. GUNDsTRoM 3,043,284

July 10, 1962 VALVE ROTATOR Filed May 29, 1961 United States :id Patented July 10, 1962 Filed May 29, 1961, Ser. No. 113,466

6 Claims. (Cl. 12S-9i?) This invention relates generally to valve rotators and refers more particularly to rotators for the valves of internal combustion engines.

The valves of Ian internal combustion engine engage and disengage their seats many times each minute and in time will pit and burn if they engage the seat in the same position. Accordingly, it is an essential object of this invention to provide `an improved means for rotating the valves of an internal combustion engine during the operation thereof so that the engaging surfaces of the valve and its seat are constantly changing.

Another object is to vprovide Aa valve rotator which utilizes the inherent twisting motion of the conventional return spring for the valve to provide the torque necessary `for rotation.

Another object is to provide a one-way clutch connection between the springend the valve to transmit twist from the spring to the valve in one direction only. Since the inherent twist of the spring is in one direction during contraction and in the opposite direction during eXpansion, the valve would oscillate back and forth and return substantially to the same position without the one-way clutch.

Another object is to provide "a spring retainer rotatably mounted on the valve Iand engaging the spring, to be subjected to the twisting motion thereof, and to provide Ithe one-way clutch between the retainer and the valve. Accordingly, the twist of the spring is transmitted to the retainer in both directions, but in only one direction is the valve rotated with the retainer.

Another object is to provide the retainer in a form which encircles the stern of the valve, and to employ a coil spring as the one-way clutch, the coil spring encircling the valve stem and secured at one end to the retainer.

Another object is to provide a member for rotatably securing the retainer to the valve stem, having a bearing part over the end of the valve stem adapted to be contacted by the rocker which is normally employed to move ythe valve in opposition to the return spring.

Another object is to provide a valve rotator which is simple and inexpensive yand adds little or no weight to the conventional valve mechanism.

Other objects and features of the invention will become apparent ,-as the following description proceeds, especially when considered with the accompanying'drawing, where- 1n:

FIGURE 1 is a fragmentary sectional View of structure embodying my invention.

FIGURE 2 is an enlarged fragmentary view of a portion of FIGURE l.

FIGURE 3 is la sectional view taken on the line 3 3 of FIGURE 2.

FIGURE 4 is a sectional Niew taken on the line 4 4 of FIGURE 2.

FIGURE 5 is similar to FIGURE 2 but shows a modication.

Referring now more particularly to the drawing and especially to FLIGURES 1-4, the engine block is generally indicated at rand defines a seat 12 surrounding a port leading to an engine cylinder. The valve 14 has a head 16 adapted to engage the seat 12 in closed position, and an elongated stem 18. The stem is guided for axial sliding movement Iby a sleeve 20 secured to the engine block.

The valve 14 is axially'reciprocable between the closed position shown in FIGURE 1 and an open position in Z which the valve head l.lr6 is spaced beneath seat l2. A rocker 22 engages the upper end of. the valve stem to move it from closed to open position.

A return coil spring 24 encircling valve stem 18 is provided to urge the valve to closed position, being conrpressed between a retainer 26 carried by the valve stem and the engine block 10. As shown in FIGURE l, the

retainer 26 has an. annular flange 23 engaged by the V upper end of the return spring, and the lower end of the spring engages the bottom of ya recess 30 in the engine block.

A key 32 is provided for mounting the retainer 26 on the valve stem so that the retainer is constrained to move axially as a unit with the Valve but can rotate relative thereto. The key 32 is formed in two half-sections 34 'and 36 and the inner semicylindrical surface of each of the key sections rotatably engages the stem of the Valve.

Each key section has one or more ribs 3S which projectinwardly from the cylindrical surface thereof to engage in a reduced portion 4d of the stem, thereby preventing relative axial movement between the key sections and the stem. The outer su-rfaces of the key sections are frustoconical and tapered to the same ydegree as the inner surface of the retainer to have a close fit therewithin.

The retainer 26 is generally cup-shaped and surrounds the valve stem, and its bottom wall 42 is apertured to rotatably receive the valve stem.

FIGURES 2 and 4 show a slight clearance between the sections 34 and 36 of the key and the valve stem i8. Actually the clearance shown is exaggerated for purposes of' illustration. It is only necessary that there be complete freedom of relative rotation between te key sections and the valve stem.

According to this construction, the retainer 26 and key will normally rotate together because of the close fit between their frusto-conical surfaces, and they will rotate open to the aperture therein, and ya coil spring 46 is disposed in the recess. -The coil spring closely encircles the stem of the valve and has one end 48 secured in a hole 50 in the retainer. Preferably this end of the spring is permanently secured to the retainer as for example by spot-welding.

It is well known that when a coil spring contracts or expands, its ends twist Vor rotate relative to each other. Hence when the return spring 24 is compressed, it rotates the retainer 26 in one direction and when it expands or elongates, it rotates the retainer in the opposite direction. This results from the pressure frictional engagement between the upper end of the spring and the flange 28 of the retainer. Coil spring 46 acts as a one-way clutch between the retainer 26 and the valve stem. When the retainer rotates in one direction (clockwise in FIGURE 3), the clutch spring 46 tightens on the valve stem, caus-l ing the two to rotate together. However, when the retainer 26 turns in the opposite direction, the clutch spring 46 merely slides over the surface of the valve stem.

According to this construction, during one half of the cycle of the valve, that is, during either its opening movement or its closing movement, it will be rotated a small increment in one direction, while during the remaining portion of the cycle, it will not be rotated. It does not matter which portion of the cycle the valve is rotated. Thus, the clutch 46 could be arranged to grip the valve stem during compression of the return spring 24, or it could be reversed to grip during expansion of the return spring; gripped and rotated during one part of the cycle, that is,

Vwhen the torque of the return spring 24 is in one direction,

and is released and not rotated when the torque of the return spring is in the opposite direction. Without the one-way clutch action of Vspring 46, the valve stem Would be rotated by twist of the return spring 24 in one direction during compression thereof, and it would be returned in the opposite direction by the reverse twist of the return spring V24 upon expansion thereof. The valve would return substantially to its initialV position and hence the engagement of the valve head and seat surfaces will be substantially the same.

FIGURE 5 illustrates a modification ofthe invention in which the key sections 34 and 36 have extensions which project Iabove and across the upper end of the valve stem to provide a bearing surface for the rocker arm. The

Y FIGURE 5 construction is more eicient at low speeds of engine operation, where the rocker might otherwise have the effect of a drag on the turning of the valve stem. At high speeds, both forms of the invention are equally -erlicient Y According to this invention, an extremely simple device is provided for rotating the valve during operation so that the surface engagement between the valve head and seat is constantly changing. The device is simple and inexpensive and adds little or no weight to the conventional valve mechanism.

What I claim as my invention is: Y

' 1. A valve rotator for use in an internal combustion engine, comprising a reciprocable member, a yretainer member rotatably mounted on said reciprocable member for reciprocation as a unit therewith, a coil spring e11- circling said reciprocable member and engaging said retainer member to contract and expand in response to the movement of said reciprooable member, said spring due to 2. The combination defined in claim 1, wherein said one-way drive is a coil spring.

3. The combination defined inV claim l, wherein said one-way drive between said members is a coil spring encircling the one and secured at one end to the other so that rotation of said retainer member in said one direc- The important thing is that the Valve stem is v 4 tion by said first-mentioned coil spring causes said secondmentioned coil spring to frictionally grip the member it encircles whereby said members rotate together and rotation of said retainer member in the opposite direction by said first-mentioned coil spring causes said secondmentioned coil spring to release the member it encircles. 4. A valve rotator for-'an internal combustion engine, comprising an elongated member supported for reciprocation in opposite directions, a retainer rotatably mounted on said elongated member for reciprocation as a unit therewith, `a coil spring encircling said elongated member and at one end engaging said retainer to contract and expand in response to the movement of said elongated member, said spring due to its inherent twisting motion during contraction and expansion acting to rotate said retainer in opposite directions, and a oneway clutch drive between said retainer 7and said elongated member to transmit twist from said spring to said elongated member in one direction only, said one-way clutch drive comprising a coil spring encircling said elongated member and secured at one end 'to said retainer so that rotation of said retainer in said one direction by said first-mentioned coil yspring causes said second-mentioned coil spring to -frictionally gripsaid elongated member whereby said member is rotated with said retainerand rotation of said retainer in the opposite direction by said first-mentioned coil spring causes said second-men- Ltioned coil Ispring fto release said member.

5. The combination defined in claim'4, wherein said retainer has an annular recess therein and said secondmentioned coil spring Vis disposed in said recess.

6.- The combination defined in claim 4, wherein said retainer is rotatably mounted on said elongated member for -reciprocation therewith by a key, and said key has ya bearing part over the end of said member for contact by a rocker adapted to move said member in opposition to said first-mentioned coil spring.

References Cited in the file of this patent UNITED STATES PATENTS Seiler June 13, 1961 

